The present invention relates to surface cleaning apparatus and in particular to such apparatus that uses a liquid to clean carpet, upholstery and the like. Further, the present invention relates to devices such as cleaning solution buckets and latching devices, useful in such equipment. Such extractors are typically used with a cleaning solution which is dispensed to a carpet either from a tank in a floor unit of the extractor or from a hose connected to a faucet, having a siphoning device to siphon concentrated cleaner, typically from a bottle, into a stream of water at a predetermined ratio. After dispensing solution to the carpet, the solution and dirt from the carpet are vacuumed up with a floor tool, sucked through a vacuum hose to a floor unit and deposited in a recovery tank. After a period of use, the recovery tank has filled or overfilled and must be emptied. Typically, this is a cumbersome, awkward and messy task, often resulting in some spillage of dirty water.
The patent issued to Cyphert (U.S. Pat. No. 4,216,563) discloses a floor unit having a castered base housing a vacuum motor, a removable cleaning solution dispensing tank and a removable dirty water recovery tank. A power cord and a vacuum hose connect to the base unit. Each tank is a specially-molded, elongated container with one small access opening on its top, near one end. The cleaning solution tank contains a pump for dispensing cleaning solution. A hose, connected to the pump, extends from the tank to a floor tool used to dispense cleaning solution. A power cord also extends from the tank and plugs into a receptacle in the base unit to provide power for the pump. The pump adds to the weight of the tank and the dispensing hose and power cord can get in the way when the tank is removed from the base unit for filling or to discard excess solution. If the solution tank is not removed for filling, a bucket or hose would be used. Either way, spillage can occur on the plug connection for the pump, resulting in a short circuit or shock. The access opening in the recovery tank is relatively small and adjacent intake and exhaust plenums built into the end of the tank. Dirty water is likely to spill into one of the plenums when the tank is tipped to be emptied, causing a mess.
The patent to Wimsatt et al. (U.S. Pat. No. 4,314,385) discloses an extractor having a floor-supported housing on casters. The housing contains a vacuum motor and a cleaning solution pump. In operation, a recovery tank is assembled on top of the base unit and a cleaning solution bag is carried inside the housing. A solution pickup hose is connected to the pump and penetrates the wall of the solution bag. Solution from the bag is pumped through a dispensing hose, to a dispenser tool and onto the carpet. Using a bag for the cleaning solution has an inherent propensity for spillage and problems. The recovery tank is essentially a deep pot with a coaxial suction conduit piercing the bottom of the pot. A vacuum hose is connected on the side of the pot. Liquid can be drawn into the pot and flow into the suction conduit, flooding the vacuum blower and floor unit housing, giving rise to significant electrical shortage and shock hazard. The pot does not have a handle, making carrying and emptying difficult. Further, dirty water can spill through the vacuum hose connector when the pot is emptied, creating a mess.
The patent to Burgoon et al. (U.S. Pat. No. 4,200,951) discloses an extractor wherein the recovery tank sits within the cleaning solution tank. If the cleaning solution tank is filled without the recovery tank in place, the solution will overflow when the recovery tank is inserted. Further, when the recovery tank is removed, solution will drip from the exterior of the recovery tank. The recovery tank has no handle, making removal, carrying and emptying difficult.
The patent to Blase et al. (U.S. Pat. No. 4,864,680) discloses compact carpet extractor. This extractor has a lower, wheeled tank body and an upper housing, latched together with over center latches. This extractor uses the faucet connection method for dispensing cleaning solution. The lower tank portion is floor-supported and fitted with casters. The upper housing contains a vacuum motor and provides for power and vacuum hose connection. Incoming water and air enter an air and water separator chamber which opens into the lower tank. The suction means also opens directly into the lower tank.
Latching devices, such as an over center latch, often find use in such extractors as well as other items where one member is to be latched to another. A typical over center latch comprises four main parts: a base part, fastened to the first of two pieces to be latched together; a lever part, pivotally connected to the base; a clasping part, pivotally connected to the lever; and a hook provision on the second of the two items to be latched together. In operation, the clasping part engages the hook and the lever is manipulated to draw the hook and base together. Typically, the clasping part is riveted to the lever and the lever part is either riveted to the base or force-fit over projecting pins on the base, engaging apertures on the lever. Such latches are disclosed by the patents to Cheney (U.S. Pat. No. 3,008,745) and Stollman (U.S. Pat. No. 3,321,230). Riveting the parts together is time-consuming and results in a connection which is loose or does not pivot freely. Force-fitting the lever causes deformation and breakage.